Title: 3232 - Osteoconductive Melt Electrospun PCL Scaffolds with Gradient And Offset Structures
Naghmeh Abbasi (Presenter)
Stephen Hamlet, Griffith University
Ryan Lee, The University of Queensland
Robert Love, Griffith University
Saso Ivanovski, The University of Queensland
Objectives: Inadequate alveolar ridge bone is a significant clinical problem when considering using dental implants. A novel additive manufacturing technique suggested as a possible strategy to regenerate lost bone relies on the incorporation of osteoblast cells into a porous gradient polymeric scaffold which imitates the variable bone density (cortical to cancellous) in the form of axial and radial structural gradients found in flat and long bone tissue architectures respectively. Our recent studies have shown that scaffolds with various offset values displayed greater cell-seeding efficiency and superior physical properties than non-offset scaffolds due to higher surface area and dense fibre layers.
Methods: In this study, we used three-dimensional melt electrospun e-poly caprolactone (PCL) scaffolds with different offset values (30%, 50%) and an increasing square pore size along the longitudinal direction from 250 to750μm produced by melt electrospinning writing. To accelerate the osteogenic process, a CaP coating modification was performed throughout the scaffold. Following osteoblast cell seeding in vitro, we assessed the correlation between osteogenic differentiation and the scaffold pore size by examination of bone-specific protein expression and ECM mineralization. We also assessed bone formation in vivo using a rodent calvarial defect model.
Results: Ofthe scaffolds, 50% offset resulted in superior bone mineralization compared to other groups. Also, higher OCN expression was observed in contrast to other proteins. Interestingly, according to micro-CT results, 500 um and gradient scaffolds displayed superior bone formation 8 weeks post-implantation. In addition, the characteristics of the bone forming tissue were determined by histological and immunohistochemical examination. Bone was presented as a compact structure in gradient structure which showed an increased new bone formation 8 weeks post-implantation probably due to a better supply of oxygen and nutrients in the compartments with the larger pores.
Conclusions: In conclusion, offset and gradient porosity scaffolds are appealing strategies to support bone regeneration applications.
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE